Check-Mac-Address
These scenarios show how the
check-mac-address feature works for the DHCP server
Test Check MAC Address
Description
The check-mac-address option filters packets if there are differences between the MAC address found at the ethernet header and the MAC address found in the DHCP packet.
To check this option, you should send packets with these differences and enable this option to see if warnings appear in your logs.
Also, this test checks how the server behaves under normal conditions.
Scenario
Step 1: Set the following configuration in DUT0 :
set interfaces ethernet eth0 address 10.0.0.1/24 set service dhcp-server shared-network dhcp subnet 10.0.0.0/24 start 10.0.0.5 stop 10.0.0.5 set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'
Step 2: Run command system journal show | tail at DUT0 and check if output contains the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Feb 19 09:39:10.424993 osdx cfgd[1859]: [55075]Completed change to active configuration Feb 19 09:39:10.425922 osdx dhcpd[222337]: Wrote 0 leases to leases file. Feb 19 09:39:10.439177 osdx OSDxCLI[55075]: User 'admin' committed the configuration. Feb 19 09:39:10.454079 osdx OSDxCLI[55075]: User 'admin' left the configuration menu. Feb 19 09:39:10.483104 osdx dhcpd[222337]: Server starting service. Feb 19 09:39:10.579407 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal show | tail'. Feb 19 09:39:11.354405 osdx dhcpd[222337]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Feb 19 09:39:12.355054 osdx dhcpd[222337]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Feb 19 09:39:12.402366 osdx dhcpd[222337]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Feb 19 09:39:12.402392 osdx dhcpd[222337]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0
Step 3: Modify the following configuration lines in DUT0 :
set service dhcp-server check-mac-address
Step 4: Run command system journal clear at DUT0.
Step 5: Run command system journal show | tail at DUT0 and check if output does not contain the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Feb 19 09:39:13.524445 osdx systemd-journald[2186]: Runtime Journal (/run/log/journal/69bd8e6fd19244c08e519827aa7e309f) is 3.0M, max 17.2M, 14.1M free. Feb 19 09:39:13.526998 osdx systemd-journald[2186]: Received client request to rotate journal, rotating. Feb 19 09:39:13.527064 osdx systemd-journald[2186]: Vacuuming done, freed 0B of archived journals from /run/log/journal/69bd8e6fd19244c08e519827aa7e309f. Feb 19 09:39:13.534063 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal clear'.
Step 6: Run command system journal show | tail at DUT0 and check if output contains the following tokens:
MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01)Show output
Feb 19 09:39:13.524445 osdx systemd-journald[2186]: Runtime Journal (/run/log/journal/69bd8e6fd19244c08e519827aa7e309f) is 3.0M, max 17.2M, 14.1M free. Feb 19 09:39:13.526998 osdx systemd-journald[2186]: Received client request to rotate journal, rotating. Feb 19 09:39:13.527064 osdx systemd-journald[2186]: Vacuuming done, freed 0B of archived journals from /run/log/journal/69bd8e6fd19244c08e519827aa7e309f. Feb 19 09:39:13.534063 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal clear'. Feb 19 09:39:13.602536 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal show | tail'. Feb 19 09:39:13.704357 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal show | tail'. Feb 19 09:39:14.518263 osdx dhcpd[222393]: MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01) Feb 19 09:39:15.574262 osdx dhcpd[222393]: MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01)
Step 7: Set the following configuration in DUT1 :
set interfaces ethernet eth0 mac '10:00:00:00:00:05' set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'
Step 8: Modify the following configuration lines in DUT1 :
set interfaces ethernet eth0 address dhcp
Step 9: Run command interfaces ethernet eth0 show at DUT1 and check if output contains the following tokens:
10.0.0.5Show output
----------------------------------------------------------------- Name IP Address Admin Oper Vrf Description ----------------------------------------------------------------- eth0 10.0.0.5/24 up up fe80::dcad:beff:feef:6c10/64
Step 10: Run command service dhcp-server show leases main | grep 10.0.0.5 at DUT0 and check if output contains the following tokens:
10:00:00:00:00:05Show output
10.0.0.5 10:00:00:00:00:05 2026/02/19 09:39:18 2026/02/19 21:39:18 2026/02/19 09:39:18
Test Check MAC Address VRF
Description
This scenario configures a DHCP server with VRF instead of regular interfaces and checks the check-mac-address option.
To check this option, you will need to send packets with differences in the Source MAC for the link layer and the client MAC from the application layer.
Scenario
Step 1: Set the following configuration in DUT0 :
set interfaces ethernet eth0 address 10.0.0.1/24 set interfaces ethernet eth0 vrf VRF0 set service dhcp-server shared-network dhcp local-vrf VRF0 set service dhcp-server shared-network dhcp subnet 10.0.0.0/24 start 10.0.0.5 stop 10.0.0.6 set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0' set system vrf VRF0
Step 2: Run command system journal show | tail at DUT0 and check if output contains the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Feb 19 09:39:26.353776 osdx cfgd[1859]: [55075]Completed change to active configuration Feb 19 09:39:26.354749 osdx dhcpd[222772]: Wrote 0 leases to leases file. Feb 19 09:39:26.365899 osdx OSDxCLI[55075]: User 'admin' committed the configuration. Feb 19 09:39:26.405344 osdx OSDxCLI[55075]: User 'admin' left the configuration menu. Feb 19 09:39:26.411713 osdx dhcpd[222772]: Server starting service. Feb 19 09:39:26.544535 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal show | tail'. Feb 19 09:39:26.850524 osdx dhcpd[222772]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Feb 19 09:39:27.851560 osdx dhcpd[222772]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0 Feb 19 09:39:27.910687 osdx dhcpd[222772]: DHCPDISCOVER from 10:00:00:00:00:02 via eth0 Feb 19 09:39:27.910712 osdx dhcpd[222772]: DHCPOFFER on 10.0.0.5 to 10:00:00:00:00:02 via eth0
Step 3: Modify the following configuration lines in DUT0 :
set service dhcp-server check-mac-address
Step 4: Run command system journal clear at DUT0.
Step 5: Run command system journal show | tail at DUT0 and check if output does not contain the following tokens:
DHCPDISCOVER from 10:00:00:00:00:02 via eth0Show output
Feb 19 09:39:29.274696 osdx systemd-journald[2186]: Runtime Journal (/run/log/journal/69bd8e6fd19244c08e519827aa7e309f) is 2.3M, max 17.2M, 14.9M free. Feb 19 09:39:29.275494 osdx systemd-journald[2186]: Received client request to rotate journal, rotating. Feb 19 09:39:29.275586 osdx systemd-journald[2186]: Vacuuming done, freed 0B of archived journals from /run/log/journal/69bd8e6fd19244c08e519827aa7e309f. Feb 19 09:39:29.287464 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal clear'.
Step 6: Run command system journal show | tail at DUT0 and check if output contains the following tokens:
MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01)Show output
Feb 19 09:39:29.274696 osdx systemd-journald[2186]: Runtime Journal (/run/log/journal/69bd8e6fd19244c08e519827aa7e309f) is 2.3M, max 17.2M, 14.9M free. Feb 19 09:39:29.275494 osdx systemd-journald[2186]: Received client request to rotate journal, rotating. Feb 19 09:39:29.275586 osdx systemd-journald[2186]: Vacuuming done, freed 0B of archived journals from /run/log/journal/69bd8e6fd19244c08e519827aa7e309f. Feb 19 09:39:29.287464 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal clear'. Feb 19 09:39:29.353870 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal show | tail'. Feb 19 09:39:29.465230 osdx OSDxCLI[55075]: User 'admin' executed a new command: 'system journal show | tail'. Feb 19 09:39:30.050591 osdx dhcpd[222828]: MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01) Feb 19 09:39:31.098367 osdx dhcpd[222828]: MAC received in DHCP packet (10:00:00:00:00:02) is different than source MAC in ethernet header (10:00:00:00:00:01)
Step 7: Set the following configuration in DUT1 :
set interfaces ethernet eth0 mac '10:00:00:00:00:05' set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'
Step 8: Modify the following configuration lines in DUT1 :
set interfaces ethernet eth0 address dhcp
Step 9: Run command interfaces ethernet eth0 show at DUT1 and check if output contains the following tokens:
10.0.0.5Show output
----------------------------------------------------------------- Name IP Address Admin Oper Vrf Description ----------------------------------------------------------------- eth0 10.0.0.5/24 up up fe80::dcad:beff:feef:6c10/64
Step 10: Run command service dhcp-server show leases VRF0 | grep 10.0.0.5 at DUT0 and check if output contains the following tokens:
10:00:00:00:00:05Show output
10.0.0.5 10:00:00:00:00:05 2026/02/19 09:39:33 2026/02/19 21:39:33 2026/02/19 09:39:33